The invention pertains to manually held chip hammers for removing oxidation and slag from a welding site wherein the hammer includes an easily replaceable point.
Chip hammers are a necessary tool for those performing arc welding. A slag forms over the welding bead, and if additional weld passes are to be taken, the slag must be first removed by a chip hammer to provide a bare metal surface for subsequent welding operations.
A conventional welding chip hammer includes an elongated head mounted on the end of a handle. One end of the hammer head is usually in the form of a chisel, and the other end of the hammer head is ground to a point. The pointed end is necessary as it permits the hammer to be effective in close quarters and to strike small portions of the slag to be removed. However, because the slag is very hard and roughly surfaced, the chip hammer pointed end quickly dulls and must be resharpened by grinding the hammer head. Continuous regrinding or resharpening the pointed hammer head end is time consuming and depletes the mass of the hammer head periodically requiring discarding of the chip hammer for replacement by an entirely new hammer including head and handle.
Accordingly, conventional weld chip hammers create an expensive non-obvious cost in arc welding operations due to the time required to grind and resharpen hammer head points, and as dull points do not effectively remove many types of slag configurations, defective welds may result from dull chip hammer points.
Heretofore, the aforedescribed problem with respect to welding chip hammer pointed ends has not been successfully solved.
It is an object of the invention to provide an inexpensive welding chip hammer having a replaceable sharp point eliminating the necessity to regrind or discard welding chip hammers because of dull points.
Another object of the invention is to provide a welding chip hammer having a replaceable sharp point wherein the point is formed of an inexpensive commercially available hardened nail, and the practice of the invention substantially reduces welding costs arising from dull welding chip hammers.
A welding chip hammer in accord with the invention includes the usual elongated hammer head having a chisel configuration at one end, and a point at the other. A handle stem is connected to the head intermediate its ends and a handle grip is attached to the outer end of the stem. In this sense, the general configuration of a chip hammer in accord with the invention corresponds with a conventional chip hammer, and no new skills need to be developed in using the chip hammer constructed in accord with the inventive concepts.
The chip hammer of the invention departs from conventional construction in that the non-chisel end of the head is provided with attachment means by which a sharp replaceable point may be quickly affixed to the hammer head end by the use of conventional tools and ordinary mechanical skills.
The replaceable chip hammer point attachment means includes a blind threaded hole formed in the hammer end usually coaxial with the hammer head axis. The threaded hole terminates in a closed end. Two embodiments of attachment means within the inventive concepts are illustrated. In one embodiment, a stud is threaded into the head threaded hole. In the other embodiment, a fitting is threaded into the hole for maintaining the point in position.
The point removably attached to the hammer head end is preferably in the form of a conventional hardened nail having a head defining a shoulder at one end, and a pointed end at the other. Such a hardened nail, usually of approximately two inches in length, is readily available at most hardware stores as the same are used to be driven into concrete by hammer or explosive charge. Such nails have a high strength, and are capable of maintaining a sharp point over long periods of time when used to engage arc welding slag.
In one embodiment, a threaded cap is mounted on a threaded stub screwed into the head hole and the cap has a hole therein wherein the pointed end of the nail is inserted through the cap hole, and the cap maintains the nail headed end against the stud outer end, which defines an anvil surface to limit nail movement toward the hammer head. Preferably, an annular washer of a resilient construction is located within the cap about the nail to align the nail within the cap prior to tightening of the cap, and give additional lateral support to the nail.
In the other embodiment of the invention, a tubular threaded fitting receives the nail pointed end and is of a length sufficiently less than the nail length so that the nail point extends beyond the fitting. The diameter of the fitting thread is less than the diameter of the nail head wherein threading of the fitting into the hammer head threaded hole results in the nail head being firmly held against the bottom surface of the head threaded hole which defines an anvil surface preventing nail movement. The extension of the nail pointed end past the fitting makes the nail pointed end available for weld slag chipping purposes.
Preferably, the hammer grip includes an interior hollow chamber having a closeable opening wherein spare points may be stored within the chip hammer grip for quick use at the welding site.
A welding chip hammer constructed in accord with the invention provides an inexpensive welding tool capable of maintaining a sharp point during use, and it is to be appreciated that the objects and advantages of the invention have been achieved.